1. Field of the Invention
The present invention relates to a plasmid, and particularly to a plasmid capable of propagating in Coryneform glutamic acid-producing bacteria.
2. Description of the Prior Art
Coryneform glutamic acid producing bacteria, so-called "Coryneform bacteria", are known to produce substantial amounts of L-glutamic acid, and mutants of the Coryneform glutamic acid producing bacteria produce amino acids such as lysine and purine nucleotides such as inosinic acid. Therefore, they are of great importance to the fermentation industry.
The recently developed gene splicing techniques can successfully be applied to the breeding or improving of industrial microorganisms, especially in the case of Escherichia coli. It has been difficult, however, to apply gene splicing techniques for the breeding or improving of industrial microorganisms or the like of Coryneform glutamic acid-producing bacteria, since suitable plasmids useful for the construction of such industrially useful Coryneform glutamic acid producing bacteria have not yet been developed.
Although a plasmid capable of propagating in Coryneform glutamic acid-producing bacteria was reported in Agric. Biol. Chem., 43, 867, (1979), the molecular weight of the known plasmid is 37 megadalton and is too large and inconvenient to use for construction of industrial microorganisms of Coryneform bacteria by gene splicing techniques.
A need, therefore, continues to exist for the development of a novel plasmid useful for the breeding or improving of industrial microorganisms of Coryneform glutamic acid-producing bacteria.